®
SPX4040
Precision Micropower 2.5V ShuntVoltage Reference
FEATURES
■
Trimmed Bandgap to 0.5% and 1%
■
Wide Operating Current 160µA to 15mA
■
Extended Temperature Range:
-40°C to 85°C
■
Low Temperature Coefficient 100 ppm/°C
■
Replacement in for LM4040
APPLICATIONS
■
Battery Operating Equipment
■
Adjustable Supplies
■
Switching Power Supplies
■
Error Amplifiers
N/C 1
8
CATHODE
N/C 2
SPX4040
8 Pin nSOIC
7
N/C
N/C 3
6
5
N/C
N/C
ANODE 4
Now Available in Lead Free Packaging
■
Single Supply Amplifier
■
Monitors / VCRs / TVs
■
Personal Computers
DESCRIPTION
The SPX4040 is a 2-terminal, temperature compensated, bandgap voltage reference that
provides a fixed 2.5V output for input currents between 160µA and 15mA. The bandgap voltage
(2.5V) is independently trimmed from the output voltage to achive a very low temperature
coefficient. This trimming technique gives a stable device over the full temperature range
(100ppm/°C).
The SPX4040 is available in 3 pin TO-92, 3 SOT-23 and 8 pin NSOIC packages. The operating
temperature range is -40°C to 85°C. The SPX4040 advanced design eliminates the need for an
external stabilizing capacitor while ensuring stability with any capacitive load, making it easy to
use.
TYPICAL APPLICATIONS CIRCUIT
Cathode (K)
R
+
-
R
2.5V
Anode (A)
Date: 1/19/05
SPX4040 Micropower 2.5V Shunt Voltage Reference
© Copyright 2005 Sipex Corporation
1
ABSOLUTE MAXIMUM RATINGS
Anode-Cathode Forward Current, (<10ms) I
AK
............................. 10mA
Anode-Cathode Reverse Current I
KA
........................................... 20mA
Continuous Power Dissipation at 25°C P
D
TO-92 ..................................................................... 550mW
SOT-23 .................................................................. 300 mW
SOIC-8 .................................................................... 525mW
Junction Temperature T
J
........................................................... 150
°C
Storage Temperature T
STG
.............................................. -65 to 150
°C
TYPICAL THERMAL RESISTANCES
PACKAGE
TO-92
SOT-23
SOIC-8
0
JA
0
JC
TYPICAL DERATING
6.3 mW/°C
1.7 mW/°C
5.7 mW/°C
160°C/W 80°C/W
575°C/W 150°C/W
175°C/W 45°C/W
Typical deratings of the thermal resistances are given for ambient
temperature >25°C.
NOTE:
Stresses greater than those listed under ABSOLUTE MAXIMUM
RATINGS may cause permanent damage to the device. This is a stress
rating only and functional operation of the device at these or any other
conditions above those indicated in the operational sections of this
specification is not implied. Exposure to absolute maximum rating condi-
tions for extended periods may affect reliability.
ELECTRICAL CHARACTERISTICS
Electrical characteristics at I
N
= 1000µA and T
A
= +25°C unless otherwise specified.
PARAMETERS
Reverse Breakdown
Voltage
Reverse Breakdown
Tolerance
Output Impedance
Noise Voltage
Tempco
Turn-on Setting
Temp. Range (ambient)
0.1KHz≤f≤10Hz
Note 1
1.0% of V
OUT
0.16
-40
30
15
85
0.16
-40
CONDITIONS
I
R
= 500
µA
I
R
= 500µA
-40°C < T
A
< 85°C
0.60
15
100
30
15
85
MIN
2.4875
TYP
MAX
MIN
2.475
TYP
2.500
MAX
2.525
±25
±49
0.60
15
100
0.8
UNITS
V
mV
mV
Ω
µV
p-p
ppm/°C
µSec
mA
°C
SPX4040A-2.5
2.500 2.5125
±12
±29
0.8
SPX4040-2.5
Operating Current Range Note 2
Notes:
1. Three-point measurement guarantees the error band over the specified temperature range.
2. Optimum performance is obtained at current below 1000µA.
CALCULATING AVERAGE TEMPERATURE COEFFICIENT (TC)
ppm
0
%
0
mV
0
∆V
KA
TC in mV/°C =
∆
T
∆V
KA
(mV)
∆T
A
-10
5000
0.5
TC in % /°C =
(
∆V
KA
∆V
KA
at 25°C
)
x 100
∆T
A
0
15
30
45
60
75
85
TC in ppm/°C =
(
∆V
KA
∆V
KA
at 25°C
∆T
A
)
x 10
6
Junction Temperature (°C)
0.07 mV/°C
0.003 %/°C
27 ppm/°C
Figure 1. V
KA
VS Temperature.
Date: 1/19/05
SPX4040 Micropower 2.5V Shunt Voltage Reference
© Copyright 2005 Sipex Corporation
2
TYPICAL PERFORMANCE CHARACTERISTICS
150
V
IN
V
KA
I
K
Cathode Current (mA)
125
100
75
50
25
0
-25
-50
-75
-100
-2
V
KA
= 2.5V
0°C to 85°C
I
K
-1
0
1
2
V
KA
Cathode Voltage (V)
3
Figure 2. Test Circuit for I
KREVERSE,
V
KA
= 2.5V
270
240
210
V
KA
= 2.5V
0° to 105°C
Figure 3. High Current Operating Characteristics
70
60
I
K
Cathode Current (µA)
180
150
120
90
60
30
0
-30
-60
-1.0
105°C
25°C
-0°C
Noise Voltage nV/√Hz
50
40
30
20
10
0
V
KA
= 2.5V
I
K
= 10mA
T
A
= 25°C
1.0
2.0
V
KA
Cathode Voltage (V)
0
3.0
10
100
1K
10K
100K
f Frequency (Hz)
Figure 4. Low Current Operating Characteristics
Figure 5. Noise Voltage VS Frequency
0.150
ZKA Dynamic Impedance (Ω)
0.125
V
KA
= 2.5V
I
KA
= 1 to 15mA
f
≤
1kHz
V
IN
0.100
0.075
V
OUT
0.050
0.025
0.0
-60
-30
0
30
60
85
TA - Free Air Temperature
Figure 6. Low Frequency Dynamic Output Impedance
VS. T
AMBIENT
Figure 7. Frequency = 100kHz, I
K
= 10mA, T
A
= 25°C
Date: 1/19/05
SPX4040 Micropower 2.5V Shunt Voltage Reference
© Copyright 2005 Sipex Corporation
3
TYPICAL PERFORMANCE CHARACTERISTICS
V
IN
250Ω
V
OUT
I
K
f
p = 100kHz
50Ω
Z
KA
Dynamic Impedance (Ω)
100
T
A
= 25
°C
I
K
= 1 to 15mA
10
1.0
0.1
0.01
1K
10K
100K
1M
10M
GND
Figure 8. Test Circuit for Pulse Response
f Frequency (Hz)
Figure 9. Dynamic Output Impedance T
A
= 25°C,
I
K
= 1 to 15mA
100
10
I
KOFF
Cathode Current
1
V
KA
= 2.5V
0.1
0.01
-50
0
50
100
150
T
A
Ambient Temperature (°C)
Figure 10. Off State Leakage
APPLICATION INFORMATION
This device is designed for stable operation and
has no need of an external capacitor between
pins 4 and 8. The reference remains stable if a
bypass capacitor is used.
SOT-23
The SPX4040 in the SOT-23 package has a
parasitic Schottky diode between pin 3 and pin
1. Pin 1 of SOT-23 must float or be connected
to pin 3.
Conventional Shunt Regulator
In a conventional shunt regulator application
(see Figure 11), an external series resistor (R
S
) is
connected between the supply voltage and the
Date: 1/19/05
SPX4040. R
S
determines the current that flows
through the load (I
L
) and the reference (I
Q
).
Since load current and supply voltage may vary,
R
S
should be small enough to supply at least the
minimum acceptable I
Q
to the reference even
when the supply voltage is at its minimum and
the load current is at its maximum value. When
the supply voltage is at its maximum and I
L
is at
its minimum, R
S
should be large enough so that
the current flowing through the SPX4040 is less
than 15mA.
R
S
is determined by the supply voltage (V
S
), the
load and operating current (I
L
and I
Q
), reference's
reverse breakdown voltage (V
R
).
R
S
= (V
S
-V
R
)/(I
L
+I
Q
)
© Copyright 2005 Sipex Corporation
SPX4040 Micropower 2.5V Shunt Voltage Reference
4
TYPICAL PERFORMANCE CHARACTERISTICS
V
S
1M
I
Q
V
IN
= 15V
RS I
Q
+ I
L
2
+
7
6
8
4
LM4250C
10V
150pF
3.5M
V
R
I
L
3
_
V
OUT
22M
I
Q
SPX4040
SPX4040-2.5
1.17M
I
Q
≅
2µA standby current
Figure 11. SPX4040 Fixed Shunt Regulator Application
Figure 12. Micropower 10V Reference
30V
* I
OUT
= 5.0V
R2
SPX4040-2.5
3.0V
3k
R1
100k
C1
150pF
2
–
7
6
2.5V
SPX4040-2.5
R2
LM312
3
+
4
I
OUT
*
2.5V to 27V
Figure 13. Precision 1µA to mA Current Source
Figure 14. Reference from 3.0V Battery
V
IN
= 3.3V to 30V
LM334
4.3k
2.5V
SPX4040-2.5
Figure 15. Wide Input Range Reference
Date: 1/19/05
SPX4040 Micropower 2.5V Shunt Voltage Reference
© Copyright 2005 Sipex Corporation
5
